With momentum increasing in the use of social robots as long-term assistive and collaborative partners, humans developing social bonds with these artificial agents appears to be inevitable. In human-human dyads, social bonding plays a powerful role in regulating behaviours, emotions, and even health. If this is to extend to human-robot dyads, the phenomenology of such relationships (including their emergence and stability) must be better understood. In this paper, we discuss potential approaches towards operationalizing the phenomenon of social bonding between human-robot dyads. We will discuss a number of biobehavioural proxies of social bonding, moving away from existing approaches that use subjective, psychological measures, and instead grounding our approach in some of the evolutionary, neurobiological and physiological correlates of social bond formation in natural systems: (a) reductions in physiological stress (the ''social buffering'' phenomenon), (b) narrowing of spatial proximity between dyads, and (c) inter-dyad behavioural synchrony. We provide relevant evolutionary support for each proposed component, with suggestions and considerations for how they can be recorded in (real-time) human-robot interaction scenarios. With this, we aim to inspire more robust operationalisation of ''social bonding'' between human and artificial (robotic) agents.

翻译：随着社交机器人作为长期辅助与协作伙伴的应用势头日益增强，人类与这些人工代理建立社交纽带似乎不可避免。在人类二元互动中，社交纽带对行为调节、情绪调控乃至健康维护发挥着重要作用。若要将此延伸至人-机器人二元体，必须更深入理解此类关系（包括其形成机制与稳定性）的现象学特征。本文探讨了实现人-机器人二元体间社交纽带现象操作化的潜在路径。我们将讨论若干社交纽带的生物行为代理指标，摒弃现有依赖主观心理测量的方法，转而基于自然系统中社交纽带形成的进化、神经生物学与生理学关联特征：（a）生理应激反应的降低（"社会缓冲"现象），（b）二元体之间空间距离的缩小，以及（c）二元体间的行为同步性。我们为每个提出的组成部分提供了相应的进化论支持，并针对如何在（实时）人-机器人交互场景中记录这些指标提出了建议与考量。借此，我们旨在激发对人类与人工（机器人）代理间"社交纽带"更稳健的操作化定义。